I'm trying to learn Kotaro Oshio's song, Wings ~you are the hero~ and let me tell you, this song is hardest song that I ever encountered with. I'm having trouble playing this even from the beginning.

I knew about percussive technique but I heard Kotaro devloped his own style of percurssive technique called, Nail attacking. Could anyone explain to me what exactly is the nail attacking technique, and how can I practice it? And how is this technique used in Wings ~you are the hero~?

I'm watching tons of Kotaro's youtube vids but he makes it so easy...

Thank you very much.